Method of bonding a particle material to near theoretical density

ABSTRACT

A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts. The method may further be applied to repair a damaged or worn substrate or part, coat a particle onto a substrate, and grow single crystals of a particle material.

This application is a divisional applaication of application Ser. No.09/223,964 filed Dec. 31, 1998 now U.S. Pat. No. 6,001,304.

FIELD AND HISTORICAL BACKGROUND OF THE INVENTION

The present invention is directed to bonding particle materials, andmore particularly to reactive or nonreactive synthesis, consolidation,or joining of metallic, ceramic, intermetallic, or composite materialsto near-net shapes by application of high shear high current (1-20 kA),and high pressure (about 1 to 2,000 MPa).

Pressure-assisted consolidation or sintering generally involves heatinga particle powder compact, while applying pressure simultaneously. Thepowder compacts are typically heated externally using graphite ormolybdenum heating elements and the pressure is applied hydraulically,pneumatically or isostatically depending on the type of the process.Conventional pressure assisted consolidation techniques include hotpressing, hot isostatic pressing, hot forging, and hot extrusion. Theconventional techniques require long processing time and high chambertemperature in order to produce high-density parts. In addition, severalpreparatory steps are required, such as powder heat treatment,precompaction, canning, welding, and machining.

The field of powder consolidation includes powder particles with averageparticle sizes ranging from about 100 microns to less than 0.01 microns.In any powder consolidation process, the objective is to have minimumgrain boundary contamination, maximum density and minimum grain growth.However, powder particles with large surface area, due to their surfacecharge distribution, readily react with the atmosphere and form a stableoxide phase, which significantly affects the consolidation process. Thepresence of these oxides, moisture and other contaminants on the surfaceof the particles, limits the final density that can be achieved anddegrades the mechanical properties of the consolidated parts. Thus, itis important to reduce the surface impurities, such as oxygen and othercontaminants present on the particle surfaces.

The consolidation of powders to near theoretical density, withoutsignificant grain growth has been a difficult task because of thetendency for the grains to coarsen at elevated temperature. Attemptshave been made to consolidate powders with average particle size lessthan 0.01 microns by many techniques, such as furnace sintering, hotpressing, and hot isostatic pressing. However, the drawback is that thetotal time required for consolidation at the elevated temperature, isvery long (several hours) which leads to significant grain growth, andpoor mechanical and thermal properties.

Most refractory metals, ceramics, intermetallics and certain compositematerials, are extremely hard and require diamond-tipped tools tomachine them to final dimensions. In order to minimize expensivemachining, the powder densification process must be capable of near-netshaping. The development of a novel process that consolidates thedifficult-to-sinter materials into near-net shaped parts has been thegoal of many powder metallurgy industries.

As application opportunities continue to emerge that require materialsto perform at higher temperatures for sustained periods of time, joiningof ceramic and intermetallic materials becomes necessary to enableadvanced structure to be produced. Sinter bonding, sinter-HIP bonding,diffusion bonding are typically employed to join these advancedmaterials. However, long preparation and processing times are requiredin the conventional techniques that result in high manufacturing cost.

Ultrafine particle materials (with average particle size less than 0.01micron) have great potential in structural, electronic, thermalmanagement and optical applications since these materials exhibitsuperior performance characteristics.

Various techniques relating to compacting or sintering of powdermaterials are disclosed in U.S. Pat. Nos. 3,250,892; 3,340,052;3,598,566; 3,670,137; 4,005,956; 5,084,088; 5,427,660; and 5,529,746;and in publications—F. V. Lenel, “Resistance Sintering Under Pressure”,Journal of Metal, Vol. 7, No. 1, pp 158-167 (1955), and M. J. Tracey etal., “Consolidation of Nanocrystalline Nb—Al Powders by Plasma ActivatedSintering”, NanoStructured Materials, Vol. 2, pp. 441-449 (1993).

The prior art techniques are also not considered effective at least forthe reasons that they: are limited to producing smaller size parts,result in nonuniform distribution of temperature throughout the powdercompact, result in lower than near theoretical densities, result inundesirable grain growth, do not reactively consolidate or join thematerials, do not consolidate or join precursor particle materials,require pretreatment or presynthesis of the particle material, do notapply to ultrafine particles (<1 micron), etc.

In view of the above, there is a need in the industry for a techniquethat can rapidly consolidate, bond or join precursor or elementalparticle material to near theoretical density without requiringcomplicated preparatory steps.

OBJECTS AND SUMMARY OF THE INVENTION

The principal object of the present invention is to provide a method ofrapidly bonding a particle material to near theoretical density withminimum grain growth and to join or bond with high interface integrityand minimum microstructural distortion in the bulk material.

An object of the present invention is to provide a method of bonding aparticle material to near theoretical density and near net shape usingpulsed plasma, pressure and current.

Another object of the present invention is to provide a method in whicha particle material can be reactively or nonreactively consolidated orjoined to near-net shape and near theoretical density in a short periodof time (less than 10 minutes) with minimum grain growth.

Yet another object of the present invention is to provide a method ofbonding a particle material to near theoretical density in which oxygenand other contaminants are removed during the bonding step without anyadditional preparatory steps.

Still yet another object of the present invention is to provide a methodof bonding particle material to near theoretical density which producesbonded material or desired articles economically at reduced processingtemperature and ID time while maintaining nanometer dimensions.

An additional object of the present invention is to provide a method ofbonding a particle material to near theoretical density which producesdense near-net shape parts or articles without expensive machining.

Yet an additional object of the present invention is to provide a rapidbonding technique that can join ceramic, intermetallic, and otherdissimilar materials in a short period of time without any complicatedpreparation.

Still yet an additional object of the present invention is to provide amethod of bonding a particle material to near theoretical density whichcan produce near-net shape parts or articles directly from precursors orelemental particle material without the complicated synthesis steps.

Another object of the present invention is to provide a method ofbonding a particle material to near theoretical density bysimultaneously applying high shear or high pressure, and high currentdirectly to the particle material resulting in high heating rate (lessthan 100° C.-1,500° C. per minute), improved particle surfaceactivation, enhanced densification, uniform distribution of heat, andstrong bonding.

Yet another object of the present invention is to provide a method ofbonding a particle material to near theoretical density which can beused to bond powders with average particle size ranging from 100 micronsto 0.01 microns, without significant grain growth, by rapidly processingat lower temperature and duration.

Still yet another object of the present invention is to provide a methodof bonding a particle material to near theoretical density which doesnot require the use of any binders or additives for producing desiredshapes.

An additional object of the present invention is to provide a method ofbonding a particle material to near theoretical density which producesnear-net shape, high density ceramic or other material parts by using acombination of “sol-gel” precursor and a reactive gas in the presence ofpulsed and steady electric field.

Yet an additional object of the present invention is to provide a methodof bonding a particle material, such as B₄C/SiC, Ti B₂/ BN, andAl₂O₃/AIN.

An additional object of the present invention is to provide a method ofrapidly bonding diamond and coated diamond powders into near-net shapedparts or articles.

Yet an additional object of the present invention is to provide a methodof bonding a particle material to near theoretical density which canproduce near-net shape parts of any desired geometry, such ascylindrical, cubic, rectangular, hemispherical, tubular, or anycombination thereof.

Still yet additional object of the present invention is to provide amethod of bonding a particle material to near theoretical density bycreating interparticle plasma which controls the undesirable graingrowth, reduces the densification temperatures, and significantlyimproves the properties of the bonded material.

A further object of the present invention is to provide a method ofproducing an article having a near-net shape and near theoreticaldensity and a length of less than one-half inch to six inches or more,or a diameter of less than one-half inch to six inches or more.

Yet a further object of the present invention is to provide a method ofproducing near-net shaped articles having improved properties, rapidlyand at significantly lower manufacturing costs.

Still yet a further object of the present invention is to provide amethod of bonding a particle material by producing interparticle plasmathat controls particle grain growth, reduces densification temperaturesand improves the overall properties of the bonded material.

An additional object of the present invention is to provide a method ofbonding a particle material which can be used to restore or repairdamaged parts or articles.

Yet an additional object of the present invention is to provide a methodof bonding a particle material which can be used to coat or clad aparticle material to a surface.

Still yet an additional object of the present invention is to provide amethod of bonding a particle material which can be used to grow singlecrystals of a particle material.

In summary, the invention relates to reactive and non-reactivesynthesis, consolidation, sintering, joining, or bonding process ofparticle material into near-net shape and near theoretical density usinghigh shear, high pressure (less than 1-2,000 MPa) and high current (1-20kA).

In the process of the invention, the materials to be consolidated orjoined, are placed preferably in a graphite die and punch assembly. Thedriving force for densification and joining is provided by passingcurrent directly through the particle material, while simultaneouslyapplying high shear and high pressure in separate steps. High shearforce in combination with pulsed electric power is initially applied tothe particle material to generate electrical discharge that activatesthe particle surface by evaporation of oxide film, impurities, andmoisture. Subsequently, bonding is accomplished by resistance heating atthe contact points between the activated particles in the presence ofhigh pressure. The time and temperature required for consolidation orjoining is lowered as high current density is applied in addition tohigh shear and high pressure (up to 2,000 MPa), which leads to localizedheating and plastic deformation at interparticle contact areas. Therapid sintering, which preferably lasts for less than ten minutes,prevents grain growth and allows the particles to retain their initialmicrostructure.

The unique feature of the present process is the simultaneousapplication of pulsed current and high shear on the particle materialresulting in surface heating of the particles to very high temperaturesfor short periods of time resulting in a localized plasma which enhancesthe rupturing of the surface oxide layers and facilitates rapiddiffusion at the surface of the particles. The temperature of theparticle material remains low, thereby minimizing the grain growth andthe processing temperature. Application of the shear forces duringsurface heating of the particles results in an abrasive action betweenthe particles to further facilitate rupturing of the surface oxide layerand redistribution of the particles. High shear causes deformation ofthe powder particles, agglomeration of the particles and since they arein intimate contact it reduces the consolidation temperature. Reducedconsolidation temperature results in reduced grain growth and improvedperformance.

It is noted herewith that, as used herein, the term “bonding” includes,but is not limited to, reactive or nonreactive joining of generallysolid materials, and reactive or nonreactive consolidation, sintering orsynthesis of particles or powder materials. Likewise, the term “particlematerial”, includes, but is not limited to, particle material in anyform, such as solid, liquid, powder, gas, fluid, etc. Preferably, theparticle material includes metallic, ceramic, intermetallic, alloy,composite, coated or uncoated powders, porous materials, partiallydense, and fully dense substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, novel features and advantages of thepresent invention will become apparent from the accompanying detaileddescription of the invention as illustrated in the drawings, in which;

FIG. 1 is a schematic representation of an apparatus that is utilized incarrying out the method of the present invention;

FIG. 2 is a schematic representation of the pulsed, alternating pulsed,alternating DC and steady DC current flow pattern of the output from thepower supply; and

FIGS. 3-5 are schematic illustrations of the steps in carrying out themethod of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As best shown in FIGS. 1 and 3, the particle material PM, to beconsolidated or joined, is placed in a chamber, such as a punch and dieassembly D, preferably a graphite or carbon-carbon composite dieassembly, and the plungers 10 and 12 are inserted on both sides.

The particle material is preferably a coated or uncoated particlepowder, or a solid substrate. The assembly D is then placed in a chamberC with controlled atmosphere and pressure. In particular, a vacuum ispreferably created in chamber C via conduits 14 and 16. The treatment ofthe particle material PM in the vacuum causes improved removal of oxide,moisture and other contaminants from the particle or solid substratesurface, and results in a product with improved and better properties,such as substantially enhanced purity. The conduits 14 and 16 alsopermit injection of reactive gases, such as nitrogen, ammonia, methane,oxygen, hydrogen, etc., for ‘in situ’ reactive consolidation or joiningof various materials. Inert gases, such as helium, argon, etc., may alsobe injected into the chamber C.

A hydraulic piston (not shown) is lowered on the top graphite plunger 10to hold the entire assembly together and to provide a path for thecurrent to flow. Once sufficient particle contacts have beenestablished, pulsed current is applied using a power supply PS. Thevoltage varies from about 1V-100V and the current from about 1-20 kA.Preferably, the voltage varies from about 1-30V and the current fromabout 1-8,000 amps. The voltage depends on the electrical resistively ofthe die, plunger, and the materials to be consolidated or joined, andthe current depends largely on the size of the powder compact. Thepulsing rate can vary from about 1 to 1000 Hz, and preferably from about10-100 Hz, and the pulsing duration from about less than 1-600 minutes,and preferably from about 5-30 minutes.

As pulsed current is applied, the top graphite plunger 10 is rotated ina clockwise direction (see arrow X in FIG. 4) and the bottom plunger 12is rotated in a counterclockwise direction (see arrow Y in FIG. 4), togenerate high shear between the particles. The rotation of the plungersis preferably controlled from 1 to 10 revolutions per minute, and thepressure from about less than 1-2.000 MPa, and preferably from about10-200 MPa. The surface activation of the particles results in theoutgassing of volatile species via conduits 4 and 16.

Subsequently, as shown in FIG. 5, a steady DC current in combinationwith axial pressure (see arrows Z in FIG. 5) is applied to achieve rapidconsolidation or joining of the particle material to form particlecompact PC. The direct current value varies from about 1-20 kA, andpreferably 1-8 kA, depending on the material and the size. The durationof direct DC current varies from about 5 to 60 minutes. The temperatureattained during resistance heating varies from about less than 500° C.to over 2500° C., and is controlled by the amount of current flowingthrough the sample. A DC voltage may be applied in an alternating mannerto provide uniform heating of the sample from top to bottom. Pressuresof up to 2,000 MPa may be applied using the hydraulic cylinder andpiston. The shape of the die and punches determines the shape of thepart. For example, it can be cylindrical, cubic, rectangular,hemispherical, tubular or any combination of standard geometricalobjects.

It is noted herewith that the shear and axial pressures may be appliedby using one or combination of hydraulic means, pneumatic means,electric field and magnetic field.

Since the shape of the dies and punches determine the final shape of theconsolidated or joined part dies and punches are designed according tothe required specifications for rapid near-net shape fabrication. Thetechnique of the invention has been used to reactively consolidatemetallic particle material, such as iron, cobalt, nickel, tungsten,rhenium; ceramics, such as silicon carbide, aluminum nitride, titaniumdioxide, titanium diboride and aluminum dioxide; intermetallics, such asiron aluminides and molybdenum disilicide; and composite particlematerial, such as tungsten carbide cobalt, tungsten-copper,molybdenum-copper, and iron cobalt-silicon carbide.

The process has also been used to reactively join ceramics, such assilicon carbide/silicon carbide (SiC/SiC) and silicon carbide/alumina(SiC/Al₂O₃); intermetallics, such as molybdenum-disilicide (MoSi₂/MoSi₂)and iron aluminide/iron (FeAl/Fe); and dissimilar metals, such asiron/nickel (Fe/Ni), copper/boron nitride (Cu/BN), andtungsten/molybdenum (W/Mo). The technique of the invention provides arapid near-net shape process that is capable of reactively ornonreactively consolidating or joining various particle materials tonear theoretical density with minimum grain growth.

The method of the invention may be applied to produce near-net, highdensity samples or articles having a length of from about less thanone-half to six inches or more, and a diameter of from about less thanone-half to six inches or more.

The following Table 1 summarizes various parameters for carrying out themethod of the invention.

TABLE 1 Parameter Operating Range Preferred Range Temperature Roomtemperature to Room temperature to 2500° C. 3000° C. (25° C.) (25° C.)Pressure <1 MPa to 2000 Mpa 10 to 200 MPa Cycle Time <1 minute to 600minutes 5 to 30 minutes Pulsing 1 to 1000 Hz 10-100 Hz Frequency PeakCurrent 5 A to 20 kA 200 A to 20 kA Base Line 0 to 14000 A 0-4000 ACurrent 1 to 20 kA 1 to 8 kA Heating Rate 1-1500°C./minute 100-1500°C./minute Voltage 1-100 V 1-30 V

The technique of the invention may also be applied to repair metallic.ceramic, intermetallic, alloy, single crystal and composite parts bylocalized surface modification. In service, most blade tips used inturbines and compressors, cutting tool edges get damaged. It will bemore economical if the damaged part can be repaired and restored to theoriginal dimension. The part to be repaired is cleaned, depending on thesize or area of damage, powder particles or surface can be used. Thepart to be repaired and the particle material are placed in a chamberand pulsed electric current with shear, followed by steady current andhigh pressure are applied, as noted above. Bonding is ensured bylocalized diffusion of heat.

The technique of the invention may also be applied to clad powders on tometallic, ceramic, intermetallic, alloy, single crystal and compositeparts. Ceramic materials in general have high wear resistance and lowthermal conductivity. Certain applications, such as high temperatureengines, turbines, will have an increase in efficiency by coating theseparts with, for example, ceramic materials. Currently, there are onlytwo methods of accomplishing this coating, plasma spray technique andphysical and chemical vapor deposition (PVD/CVD) technique. In plasmaspray, the coating is porous and the adhesion is poor. In the PVD/CVDtechnique, not all materials can be deposited and the coating develops aparticular orientation. In accordance with the present invention, thepart to be coated with a particular or a combination of particlematerials is dip coated in a slurry and placed inside a vacuum chamberbetween the two plungers. The part is then heated using the pulsing andsteady current technique of the present invention. This results ininterparticle diffusion and bonding of particle material to thesubstrate. Thus, cladding the surface with the desired material. Thethickness and density of the coating can be controlled by controllingthe slurry concentration and the number of coating cycles.

Finally, the technique of this invention may be used to grow singlecrystals by using a combination of particle material and seed crystal.As one of ordinary skill in the art would be aware, applications ofsingle crystals are steadily increasing and new techniques are beingdeveloped to produce single crystals. The present techniques of growingsingle crystals from vapor deposition or from molten metals areexpensive and very sensitive to contamination and process parameters.Single crystals exhibits certain properties which cannot be attained byany other densification or processing techniques of the same material.Using the process of the invention, ultrafine powders can be packedalong with a seed is single crystal and placed preferably in a graphitedie. Using a combination of pulsed power and steady current, as notedabove, it is possible to grow single crystals.

The following Examples are provided to illustrate the invention, but itis understood that the invention is not limited thereto.

EXAMPLE 1

Rhenium powders (average particle size 25 microns) were consolidated tonear theoretical density (96-99%) without significant grain growth byprocessing at 1100-1400° C. and 400-600 MPa with isothermal holding timeof 1-10 minutes.

The sample size ranged from ½ to 2″ in length and ½ to 1″ in diameter.

EXAMPLE 2

Tungsten powders (average particle size 0.2 to 4 microns) wereconsolidated to near theoretical density (96-99%) without significantgrain growth by processing at 1100-1600° C. and at 10-900 MPa for 1-10minutes. The sample size ranged from ½ to 2″ in length and ½ to 1″ indiameter.

EXAMPLE 3

Ultrafine iron powders (average particle size <0.1 microns) wereconsolidated to near theoretical density (96-99%) without significantgrain growth by processing at 500-950° C. and 50-900 MPa for 1-5minutes. The sample size ranged from ½ to 2″ in length and ½ to 1″ indiameter.

EXAMPLE 4

Molybdenum-Copper composite powders (average particle size 1-3 micron)were consolidated to near theoretical density (95-97%) at 900-1150° C.and at 50-900 MPa in less than 20 minutes. The sample size ranged from ½to 2″ in length and ½ to 1″ in diameter.

EXAMPLE 5

Tungsten-carbide cobalt powders (with average particle size <1.0 micronto up to 12 microns) were consolidated to near theoretical density(96-99%) at 1300° C and at 700 MPa in less than 5 minutes. The samplesize ranged from ½ to 2″ in length and ½ to 1″ in diameter.

EXAMPLE 6

Aluminum nitride powders (<20 microns) were consolidated to neartheoretical density (91-99%) without significant grain growth byprocessing at 1500-1600° C. and at 30-70 MPa for 1-5 minutes. The samplesize ranged from ½ to 2″ in length and ½ to 1″ in diameter.

EXAMPLE 7

Aluminum powders (<30 microns) were consolidated to near theoreticaldensity (96-99%) without significant grain growth by processing at500-600° C. and at 30-70 MPa for 1-5 minutes. The sample size rangedfrom ½ to 2″ in length and ½ to 1″ in diameter. Hollow tubes were alsoconsolidated with an internal diameter of ¼″ and an outer diameter of 1inch. The length of the tube was 1 inch.

EXAMPLE 8

Molybdenum disilicide powders (<10 microns) were consolidated to neartheoretical density (92-96%) without significant grain growth byprocessing at 1700-1900° C. and at 30-70 MPa for 1-5 minutes. The samplesize ranged from ½ to 2″ in length and ½ to 1″ in diameter.

EXAMPLE 9

Sol-gel precursor consisting of organometallic polymer of Si—C—O—H wasdecomposed to SiC by applying pulsed DC for 15 minutes at 200 ampsfollowed by final consolidation to near theoretical density (95-96%) at2100° C. and at 70 MPa for 30 minutes. The sample size was ½-1″ inlength and 1″ in diameter.

EXAMPLE 10

Tantalum powders (<45 microns) were consolidated to near theoreticaldensity (92-98%) without significant grain growth by processing at1400-1600° C. and at 30-70 MPa for 1-8 minutes. The sample size rangedfrom ½ to 2″ in length and ½ to 1″ in diameter. Hollow tubes were alsoconsolidated with an internal diameter of ¼″ and an outer diameter of 1inch. The length of the tube was 1 inch.

EXAMPLE 11

Joining of SiC/Al₂O₃ was achieved directly from SiC and Al₂O₃ powders byplacing 0.5″ long Al₂O₃ green compact on top of 0.5″ long SiC greencompact, and consolidating them at 2000° C. and 65 MPa for 20 minutes.Dense (98% of theoretical) and strongly bonded compact was producedwithout the use of additives and binders.

EXAMPLE 12

Titanium and boron powders were mixed in the ratio of 1.2 and combustionsynthesized to form TiB and TiB₂ by applying pulsed DC current for <5minutes at 2000 amps. The powders were then consolidated to hollowcylinders (¼ inch inner diameter, 1 inch outer diameter and 1 inch long)at 2000° C. and 50 MPa for minutes. The density of the finalconsolidated part was 95% of the theoretical density.

EXAMPLE 13

Diamond powders were consolidated at 800-1 300° C. and under a pressureof 30-70 MPa with a hold time less than 5 minutes. The sample sizeranged from ½ to 1″ in length and ½ to 1″ in diameter. Coated diamondpowders such as cobalt coated diamond and nickel coated diamond powderswere also consolidated under similar conditions.

EXAMPLE 14

Nickel aluminide powders were consolidated at 1000-1300° C. and under apressure of 30-70 MPa for 1-5 minutes. The sample size ranged from ½ to2″ in length and ½ to 2″ in diameter.

While this invention has been described as having preferred ranges,steps, materials, or designs, it is understood that it is capable offurther modifications, uses and/or adaptations of the inventionfollowing in general the principle of the invention and including suchdepartures from the present disclosure as those come within the known orcustomary practice in the art to which the invention pertains and as maybe applied to the central features hereinbefore set forth, and fallwithin the scope of the invention and of the limits of the appendedclaims.

What is claimed is:
 1. A method of repairing a substrate, comprising thesteps of: a) providing a chamber; b) placing a particle substrate to berepaired in the chamber; c) placing a particle material at a desiredlocation on the substrate; d) applying a shear force to the substrateincluding the particle material for a predetermined time period; e)substantially simultaneously with the step c) application of shearforce, applying a pulsed current to the substrate including the particlematerial for a predetermined time period; f) applying a pressure to thesubstrate obtained in step e); and g) substantially simultaneously withthe step f) application of pressure, applying a steady current forbonding the particle material to the substrate.
 2. The method of claim1, wherein: the substrate is comprised of a material selected from thegroup consisting of metal, ceramic material, intermetallic material,alloy, single crystal, and composite material.
 3. The method of claim 1,wherein: the step d) comprises applying a shear force of about 5-50 MPa.4. The method of claim 1, wherein: the step e) comprises applying apulsed current of about 1-20,000 amps.
 5. The method of claim 1,wherein: the step f) comprises applying an axial pressure of about lessthan 1-2,000 MPa.
 6. The method of claim 1, wherein: the step g)comprises applying a current of about 1-20,000 amps.
 7. A method ofcoating a particle material onto a substrate, comprising the steps of:a) providing a substrate to be coated; b) providing a slurry of theparticle material; c) immersing the substrate in the slurry to therebyprovide a slurry coating thereon; d) placing the slurry coated substratein a chamber; e) applying a shear force to the slurry coated substratefor a predetermined time period; f) substantially simultaneously withthe step e) application of shear force, applying a pulsed current to theslurry coated substrate for a predetermined time period; g) applying apressure to the substrate obtained in step f); and h) substantiallysimultaneously with the step g) application of pressure, applying asteady current for coating the particle material to the substrate. 8.The method of claim 7, wherein: the substrate is comprised of a materialselected from the group consisting of metal, ceramic material,intermetallic material, alloy, single crystal, and composite material.9. The method of claim 7, wherein: the step e) comprises applying ashear force of about 5-50 MPa.
 10. The method of claim 7, wherein: thestep f) comprises applying a pulsed current of about 1-20,000 amps. 11.The method of claim 7, wherein: the step g) comprises applying an axialpressure of about less than 1-2,000 MPa.
 12. The method of claim 7,wherein: the step h) comprises applying a current of about 1-20,000amps.
 13. A method of repairing a substrate, comprising the steps of a)providing a substrate to be repaired; b) placing a suitable amount of aparticle material at a desired location on the substrate; c) applying ashear force to the substrate including the particle material for apredetermined time period; and d) applying a current to the substrateincluding the particle material for a predetermined time period forthereby bonding the particle material to the substrate.
 14. The methodof claim 13, further comprising the step of: e) applying a pressure tothe substrate obtained in step d).
 15. The method of claim 14, furthercomprising the step of f) applying a current to the substrate obtainedin step e).
 16. The method of claim 13, wherein: the step d) comprisesapplying a pulsed current substantially simultaneously with step c)application of shear force.
 17. The method of claim 15, wherein: thestep f) comprises applying a steady current substantially simultaneouslywith the step e) application of pressure.
 18. The method of claim 13,wherein: the step c) application of shear force comprises applying apressure using hydraulic means, pneumatic means, an electric field, amagnetic filed, or a combination thereof.
 19. A method of coating aparticle material onto a substrate, comprising the steps of: a)providing a substrate to be coated; b) providing a slurry of theparticle material; c) coating the substrate with the slurry; d) applyinga shear force to the slurry coated substrate for a predetermined timeperiod; and e) applying a current to the slurry coated substrate for apredetermined time period for coating the particle material to thesubstrate.
 20. The method of claim 18, further comprising the step of:f) applying a pressure to the substrate obtained in step e).
 21. Themethod of claim 19, further comprising the step of: g) applying acurrent to the substrate obtained in step f).
 22. The method of claim18, wherein: the step e) comprises applying a pulsed currentsubstantially simultaneously with the step d) application of shearforce.
 23. The method of claim 19, wherein: the step d) application ofshear force comprises applying a pressure using hydraulic means,pneumatic means, an electric field, a magnetic filed, or a combinationthereof.
 24. The method of claim 21, wherein: the step g) comprisesapplying a steady current substantially simultaneously with the step f)application of pressure.